Struct GutterOpts 

pub struct GutterOpts<G> {
    pub total_lines: usize,
    pub viewport_height: u32,
    pub gutter_fn: G,
}

Options for Context::scrollable_with_gutter.

Carries the bookkeeping arguments together so call sites become readable:

// 90% case — automatic line numbers.
ui.scrollable_with_gutter(
    &mut scroll,
    GutterOpts::line_numbers(120, 24),
    |ui, line| { ui.text(format!("line {line}")); },
);

// Custom gutter labels.
ui.scrollable_with_gutter(
    &mut scroll,
    GutterOpts::new(120, 24, |i| if i == 7 { "!".to_string() } else { String::new() }),
    |ui, line| { ui.text(format!("line {line}")); },
);

Fields

total_lines: usize

Total number of content lines.

viewport_height: u32

Viewport height in rows.

gutter_fn: G

Closure that returns the gutter label for a given absolute line index.

Implementations

impl<G> GutterOpts<G>

where G: Fn(usize) -> String,

pub fn new(total_lines: usize, viewport_height: u32, gutter_fn: G) -> Self

Build options with an explicit gutter labeling closure.

impl GutterOpts<fn(usize) -> String>

pub fn line_numbers(total_lines: usize, viewport_height: u32) -> Self

Shortcut for the 90% case: render 1-based line numbers in the gutter.

Equivalent to GutterOpts::new(total, viewport, |i| format!("{}", i + 1)) but uses a function pointer to avoid forcing the caller to name the closure type.